Berner GR Series Operating And Service Instructions page 15

 The 2"-inch flue vent is inside (concentric with) the 4" inch combustion air inlet duct. Each of the
former must be seamless and all joints must be fastened with screws and sealed with GE RTV-106
high temperature sealant (or equivalent) refer to Figure 12. The exposed 4" combustion air intake pipe
is zero clearance throughout its length.
Maximum 10 Feet of Venting
Fasten Screws (Min. one "1" Screw for 2" Flue Pipe)
4" Combustion Air Inlet Duct
Series GR
7"
Figure 11: Minimum Clearance under an Eave
With One (1) Elbow
Fasten Screws
(Min. 2 Screws
for 4" Duct)
2" Flue Pipe Should be
Concentric with the 4"
2" Flue Pipe
Combustion Air Inlet Duct
(Flue Vent)
Seal Joints With RTV Silicone
Figure 12: Venting / Combustion Air Ducting
Page 15
Venting / Combustion Air Ducting
7"
Seal Joints
With RTV Silicone
Wall Terminal
OR
6.0"
Extension
Wall Terminal
10.0"
Extension
Optional Horizontal
"Elbow Vent Terminal"
February 10, 2014